Two HDDs: one SATA, one IDE. Spares, not bootable OS partitions. Can make RAID1?

I have a ~250GB SATA drive that I like to use as a spare media/storage drive. I came upon another drive about the same size but it's IDE. I figured I'd make them one logical volume using JBOD RAID, but then figured I'd be better off mirroring them in case one dies. How do I create a RAID1 array using the existing disk w/ data (/dev/sdc1) and mirror it to the newly added disk w/ no data (/dev/sdb1)?